﻿/*   
    Copyright (C) 2009 Galaktika Corporation ZAO

    This file is a part of Ranet.UILibrary.Olap
 
    Ranet.UILibrary.Olap is a free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
      
    You should have received a copy of the GNU General Public License
    along with Ranet.UILibrary.Olap.  If not, see <http://www.gnu.org/licenses/>.
  
    If GPL v.3 is not suitable for your products or company,
    Galaktika Corp provides Ranet.UILibrary.Olap under a flexible commercial license
    designed to meet your specific usage and distribution requirements.
    If you have already obtained a commercial license from Galaktika Corp,
    you can use this file under those license terms.
*/

using System;
using System.Collections.Generic;

namespace Ranet.Olap.Mdx
{
	public sealed class MdxCaseExpression : MdxExpression
	{
		public readonly MdxObjectList<MdxWhenClause> When = new MdxObjectList<MdxWhenClause>();
		private MdxExpression _Value = null;
		public MdxExpression Value
		{
			get { return _Value; }
			set { _Value = value; _ChildTokens = null; }
		}
		MdxExpression _Else = null;
		public MdxExpression Else
		{
			get { return _Else; }
			set { _Else = value; _ChildTokens = null; }
		}
		public MdxCaseExpression()
		{
			When.ListChanged += When_ListChanged;
		}
		void When_ListChanged()
		{
			_ChildTokens = null;
		}
		public MdxCaseExpression(IEnumerable<MdxWhenClause> whenItems)
			: this()
		{
			if (whenItems != null)
				When.AddRange(whenItems);
		}
		public MdxCaseExpression(IEnumerable<MdxWhenClause> whenItems, MdxExpression elseItem)
			: this(whenItems)
		{
			_Else = elseItem;
		}
		public MdxCaseExpression(MdxExpression ValueItem, IEnumerable<MdxWhenClause> whenItems, MdxExpression elseItem)
			: this(whenItems, elseItem)
		{
			this._Value = ValueItem;
		}
		public override string SelfToken
		{
			get { return "CASE ..."; }
		}
		public static MdxToken CASE = new MdxToken("CASE");
		public static MdxToken ELSE = new MdxToken("ELSE");
		public static MdxToken END = new MdxToken("END");
		protected override void FillChilds()
		{
			_ChildTokens = new List<MdxObject>();
			_ChildTokens.Add(CASE);
			if (Value != null)
			{
				_ChildTokens.Add(IncShift);
				_ChildTokens.Add(Value);
				_ChildTokens.Add(DecShift);
			}
			foreach (var w in When)
			{
				_ChildTokens.Add(NewLine);
				_ChildTokens.Add(w);
			}
			if (Else != null)
			{
				_ChildTokens.Add(NewLine);
				_ChildTokens.Add(ELSE);
				_ChildTokens.Add(NewLine);
				_ChildTokens.Add(IncShift);
				_ChildTokens.Add(Else);
				_ChildTokens.Add(DecShift);
			}
			_ChildTokens.Add(NewLine);
			_ChildTokens.Add(END);
		}

		public override object Clone()
		{
			if (this.When == null)
			{
				return new MdxCaseExpression();
			}

			if (this.Value == null && this.Else == null)
			{
				return new MdxCaseExpression(
						(IEnumerable<MdxWhenClause>)this.When.Clone());
			}
			if (this.Value == null)
			{
				return new MdxCaseExpression(
						(IEnumerable<MdxWhenClause>)this.When.Clone(),
						(MdxExpression)this.Else.Clone());
			}

			return new MdxCaseExpression(
					(MdxExpression)this.Value.Clone(),
					(IEnumerable<MdxWhenClause>)this.When.Clone(),
					(MdxExpression)this.Else.Clone());
		}
	}
}
